Some numerator types used (specifically NumPy) decides to not
return a Python boolean for the "a != b" operation. Using the equivalent
call to bool() guarantees a bool return also for such types.
* bpo-39491: Merge PEP 593 (typing.Annotated) support
PEP 593 has been accepted some time ago. I got a green light for merging
this from Till, so I went ahead and combined the code contributed to
typing_extensions[1] and the documentation from the PEP 593 text[2].
My changes were limited to:
* removing code designed for typing_extensions to run on older Python
versions
* removing some irrelevant parts of the PEP text when copying it over as
documentation and otherwise changing few small bits to better serve
the purpose
* changing the get_type_hints signature to match reality (parameter
names)
I wasn't entirely sure how to go about crediting the authors but I used
my best judgment, let me know if something needs changing in this
regard.
[1] 8280de241f/typing_extensions/src_py3/typing_extensions.py
[2] 17710b8798/pep-0593.rst
When called on a closed object, readinto() segfaults on account
of a write to a freed buffer:
==220553== Process terminating with default action of signal 11 (SIGSEGV): dumping core
==220553== Access not within mapped region at address 0x2A
==220553== at 0x48408A0: memmove (vg_replace_strmem.c:1272)
==220553== by 0x58DB0C: _buffered_readinto_generic (bufferedio.c:972)
==220553== by 0x58DCBA: _io__Buffered_readinto_impl (bufferedio.c:1053)
==220553== by 0x58DCBA: _io__Buffered_readinto (bufferedio.c.h:253)
Reproducer:
reader = open ("/dev/zero", "rb")
_void = reader.read (42)
reader.close ()
reader.readinto (bytearray (42)) ### BANG!
The problem exists since 2012 when commit dc469454ec added code
to free the read buffer on close().
Signed-off-by: Philipp Gesang <philipp.gesang@intra2net.com>
Currently, during runtime destruction, `_PyImport_Cleanup` is clearing the interpreter state before clearing out the modules themselves. This leads to a segfault on modules that rely on the module state to clear themselves up.
For example, let's take the small snippet added in the issue by @DinoV :
```
import _struct
class C:
def __init__(self):
self.pack = _struct.pack
def __del__(self):
self.pack('I', -42)
_struct.x = C()
```
The module `_struct` uses the module state to run `pack`. Therefore, the module state has to be alive until after the module has been cleared out to successfully run `C.__del__`. This happens at line 606, when `_PyImport_Cleanup` calls `_PyModule_Clear`. In fact, the loop that calls `_PyModule_Clear` has in its comments:
> Now, if there are any modules left alive, clear their globals to minimize potential leaks. All C extension modules actually end up here, since they are kept alive in the interpreter state.
That means that we can't clear the module state (which is used by C Extensions) before we run that loop.
Moving `_PyInterpreterState_ClearModules` until after it, fixes the segfault in the code snippet.
Finally, this updates a test in `io` to correctly assert the error that it now throws (since it now finds the io module state). The test that uses this is: `test_create_at_shutdown_without_encoding`. Given this test is now working is a proof that the module state now stays alive even when `__del__` is called at module destruction time. Thus, I didn't add a new tests for this.
https://bugs.python.org/issue38076
Adds an additional assertion check based on a race condition for `test__xxsubinterpreters.DestroyTests.test_still_running` discovered in the bpo issue.
https://bugs.python.org/issue37224
Improve multi-threaded performance by dropping the GIL in the fast path
of bytes.join. To avoid increasing overhead for small joins, it is only
done if the output size exceeds a threshold.
In bpo-36264 os.path.expanduser was changed to ignore HOME on Windows.
Path.expanduser/home still honored HOME despite being documented as behaving the same
as os.path.expanduser. This makes them also ignore HOME so that both implementations
behave the same way again.
The os.putenv() and os.unsetenv() functions are now always available.
On non-Windows platforms, Python now requires setenv() and unsetenv()
functions to build.
Remove putenv_dict from posixmodule.c: it's not longer needed.
* bpo-39421: Fix posible crash in heapq with custom comparison operators
* fixup! bpo-39421: Fix posible crash in heapq with custom comparison operators
* fixup! fixup! bpo-39421: Fix posible crash in heapq with custom comparison operators
* Add three new bytecodes: LIST_TO_TUPLE, LIST_EXTEND, SET_UPDATE. Use them to implement star unpacking expressions.
* Remove four bytecodes BUILD_LIST_UNPACK, BUILD_TUPLE_UNPACK, BUILD_SET_UNPACK and BUILD_TUPLE_UNPACK_WITH_CALL opcodes as they are now unused.
* Update magic number and dis.rst for new bytecodes.
* bpo-39336: Allow setattr to fail on modules which aren't assignable
When attaching a child module to a package if the object in sys.modules raises an AttributeError (e.g. because it is immutable) it causes the whole import to fail. This now allows immutable packages to exist and an ImportWarning is reported and the AttributeError exception is ignored.
When communicate() is called in a loop, it crashes when the child process
has already closed any piped standard stream, but still continues to be running
Co-authored-by: Andriy Maletsky <andriy.maletsky@gmail.com>
Deprecate binhex4 and hexbin4 standards. Deprecate the binhex module
and the following binascii functions:
* b2a_hqx(), a2b_hqx()
* rlecode_hqx(), rledecode_hqx()
* crc_hqx()
As described in RFC 1952, section 2.3.1, the XFL (eXtra FLags) byte of a
gzip member header should indicate whether the DEFLATE algorithm was
tuned for speed or compression ratio. Prior to this patch, archives
emitted by the `gzip` module always indicated maximum compression.
Remove the buffering parameter of bz2.BZ2File. Since Python 3.0, it
was ignored and using it was emitting a DeprecationWarning. Pass an
open file object to control how the file is opened.
The compresslevel parameter becomes keyword-only.
Remove base64.encodestring() and base64.decodestring(), aliases
deprecated since Python 3.1: use base64.encodebytes() and
base64.decodebytes() instead.
pstats is really useful or profiling and printing the output of the execution of some block of code, but I've found on multiple occasions when I'd like to access this output directly in an easily usable dictionary on which I can further analyze or manipulate.
The proposal is to add a function called get_profile_dict inside of pstats that'll automatically return this data the data in an easily accessible dict.
The output of the following script:
```
import cProfile, pstats
import pprint
from pstats import func_std_string, f8
def fib(n):
if n == 0:
return 0
if n == 1:
return 1
return fib(n-1) + fib(n-2)
pr = cProfile.Profile()
pr.enable()
fib(5)
pr.create_stats()
ps = pstats.Stats(pr).sort_stats('tottime', 'cumtime')
def get_profile_dict(self, keys_filter=None):
"""
Returns a dict where the key is a function name and the value is a dict
with the following keys:
- ncalls
- tottime
- percall_tottime
- cumtime
- percall_cumtime
- file_name
- line_number
keys_filter can be optionally set to limit the key-value pairs in the
retrieved dict.
"""
pstats_dict = {}
func_list = self.fcn_list[:] if self.fcn_list else list(self.stats.keys())
if not func_list:
return pstats_dict
pstats_dict["total_tt"] = float(f8(self.total_tt))
for func in func_list:
cc, nc, tt, ct, callers = self.stats[func]
file, line, func_name = func
ncalls = str(nc) if nc == cc else (str(nc) + '/' + str(cc))
tottime = float(f8(tt))
percall_tottime = -1 if nc == 0 else float(f8(tt/nc))
cumtime = float(f8(ct))
percall_cumtime = -1 if cc == 0 else float(f8(ct/cc))
func_dict = {
"ncalls": ncalls,
"tottime": tottime, # time spent in this function alone
"percall_tottime": percall_tottime,
"cumtime": cumtime, # time spent in the function plus all functions that this function called,
"percall_cumtime": percall_cumtime,
"file_name": file,
"line_number": line
}
func_dict_filtered = func_dict if not keys_filter else { key: func_dict[key] for key in keys_filter }
pstats_dict[func_name] = func_dict_filtered
return pstats_dict
pp = pprint.PrettyPrinter(depth=6)
pp.pprint(get_profile_dict(ps))
```
will produce:
```
{"<method 'disable' of '_lsprof.Profiler' objects>": {'cumtime': 0.0,
'file_name': '~',
'line_number': 0,
'ncalls': '1',
'percall_cumtime': 0.0,
'percall_tottime': 0.0,
'tottime': 0.0},
'create_stats': {'cumtime': 0.0,
'file_name': '/usr/local/Cellar/python/3.7.4/Frameworks/Python.framework/Versions/3.7/lib/python3.7/cProfile.py',
'line_number': 50,
'ncalls': '1',
'percall_cumtime': 0.0,
'percall_tottime': 0.0,
'tottime': 0.0},
'fib': {'cumtime': 0.0,
'file_name': 'get_profile_dict.py',
'line_number': 5,
'ncalls': '15/1',
'percall_cumtime': 0.0,
'percall_tottime': 0.0,
'tottime': 0.0},
'total_tt': 0.0}
```
As an example, this can be used to generate a stacked column chart using various visualization tools which will assist in easily identifying program bottlenecks.
https://bugs.python.org/issue37958
Automerge-Triggered-By: @gpshead
On Unix, subprocess.Popen.send_signal() now polls the process status.
Polling reduces the risk of sending a signal to the wrong process if
the process completed, the Popen.returncode attribute is still None,
and the pid has been reassigned (recycled) to a new different
process.
* Reorder the __aenter__ and __aexit__ checks for async with
* Add assertions for async with body being skipped
* Swap __aexit__ and __aenter__ loading in the documentation
